Lathe



July 29.1924. 1,503.1l5 Y l.. A. CARTER LATHE Filednec. s, 1920 2 shears-sheet 1 L. A. CARTER LATHE July 29. 1924. y' 1,503,115

Filed Dec. 1920 2 sneeuwbui 2 [n ver@ 30P.'

Y f @ne of the principal Vobjects entinvention is to provide a simple and..

Patented July 29, 1924.

rscana nutren STATES i PATENT OFFICE. .A

LIONEL A. CARTER, 0F LOUIS, MISSOURI.

LATHE.

Applicationiled December 3, 1920. Serial No. 428,056.

particularly to the Vmeans for closing the n feed-nut uponthe feed-screw and for releasing it therefrom.` p

of-the -presefficient means for opening and closing the feed-nuts oflathes which can be easily operatedfand which, when operated to close the feed-nut about the feed-screw, ypositively locks thetwo halves of the feed-nut against separation under internal pressure of the feed-screw thereagainst. Another object'is to 4prevent the closing of the feed-nut'upon the feed-screw except Vin certain positions, thereby preventing operation of` both the feed-'rod and feed-screw at thesametime.L Another object is to minimize the pressure' of. lthetwo halves of the feed-nut yon the feed-:screwat the beginning of their'closingin movement, thereby preventing injury to the threads and to increase the pressure after the'threads of theV two half-nutsy are in mesh with the threads of said feed-screw.

The invention consists principallyfin improved means for opening and lclosing the feed-nut and in means for preventingthe koperation of the feed-rod 'and feed-screw at thesame time. The inventionfurther consists in the parts and arrangements of parts hereinafter described and claimed.

In the accompanyingV drawing, which .forms part of this specication, and wherein like symbolsy refer to like parts wherever they occur,

Fig. 1 is a fragmentary inside faceview of a latheapron in the region'V of the feednut, showing the adjacentportions of the feed-screw and feed-rod and a feed-nut convtrollingdevice embodying my invention, the

yfeed-nut being shown released from the feed-screw;

i Fig. 2 is aY view similar to Fig. 1, showing the feed-'nut closed upon the feed-screw Fig. 3 is Va vertical section through the apron on the line 3--3 in Figa-2; and

' Fig. 4 is a horizontal section through the apron on theline i4- 4t in'Fig. 1.` Y

yIn the accompanying drawing, 1 indicates the depending apron portion of an ordinary traveling tool-carriage, which is slidably mounted on the ways of the lathe Vbed (not shown), 2 indicates the feed-screw for moving the carriage along thevlathe bed when thread cutting; and/4 indicates the feedrod for moving vsaidcarriage when doing Y- work other than thread cutting.

The feed-nut 'comprises upper and lower .sections in the formof half-nuts 5V and 6,

which are disposed above and below the feed-screw 2 and have vertically disposed plate portions 7 and 8 formed integral therewith.` Said half-nuts are arranged for vertical sliding movement toward and away from each other at right angles tothe longi-4 tudinal axis of the feed-screw. lThe opposite l side marginal portions'of the slide plates7 and 8 of the upperV and lower half-nuts and -6 are arranged for vertical sliding movement in angular 4recesses or rabbets 9 formed in the opposing 'edges of a pair fl vertically disposed' horizontally spaced lugs V1() whichV project voutward from the inner face of the apron member 1i The side margin of the slide plates 7'and 8 of the upper and lower half-nuts are retained within the yangular recesses 9 of the lugs 10 by means of plates -11 which are secured to the face of the lugs with theirA inner side marginal'portionsoverlapping the outer side marginal portions of the slideplates, by means of cap screws 12.

The mechanism for separating or bringing the half-nuts together comprises a pair of curved links 13 and 14. The-links are disposed one. above the other between the disposed spaced lugs 10 of the apron'member with the Ylower end of the upper link 13 and the upper end of the lower link 11 adjacent to each other. VJournaledin .a horizontal bore in theapron member 1,V midway between the spacedv lugs 10 thereof, and oppositev the longitudinal axis of the feed-screw 2 is a rock shaft 15. The outer end of the shaft 15A has a rock handle 16 :mounted on Y oppositely disposed pins VVor arbors 18 and 19 which project outwardly 'from .the face ofthe disk 17 on Vopposite sides of its center. The upper Vend of the upper link 13 is pivotally mounted on a complished by a V90 degree turn of the operating handle. `lhen it is desired to close the two halves of the feed-nutv upon the feedscrew, for `the purpose of using said screw as a means for feeding the carriage, the operating handle is turned to partially rotate thel disk 17 in adirection that will cause the pivot 18 to swing downwardly and the pivot 19t@ swing upwardly, both pivots swinging ink ancarc described from the center of said disk. This swinging movement of the pivots 18 and 19,V by reason of the link connections 13 and 14 with the pivots 2O and 21 oftheftwo half sections of the feednut, causes .the two half-nuts to move toward each other and close about the feed-screw. When in this position7 the pivots 18 andk 19 of the disk 17 and the pivots 20 and 21 of ,the halffnu-ts are on a dead center, thus preventing separation ofthe half-nuts Vunder internal pressure.- f At the beginningof the closing-in movement of YKthe two Ahalf-nuts, the pressure exerted by the half-nuts upon the feed-screw is slight, 'thereby avoiding injury .to the threads, and permitting the half-nutsgjto properly seat upon the feedscrew' beforetherleverage is` increased and the centers of the pivots of .the links 13 and 1 4'eoincide.4 The adjacentend portions of the links 13 and 14, are curv.edaway from each other to enable said portions to clear .each other during thek swinging movement ofthe links.

he feed screw 2 is journaledl in a bracket 22, whiehprojects from the middle portion of the guide .plate at the end of the apron,

and feed rod 4 is journaled in a bearingr 23,

which projects from the lower end of said guide plate.

For/ ordinary work, the tool-carriage is moved by means of theusual rack and pinion feed .(not shown) ,f the feed being taken from the feed-rod. Motionv is transmitted from the feed rod to a beveledl reversing 'gear 24 through a sliding pinion 25. AThe `reversing gear 24'is journaled in a suitable bearingv in the apron member", and the slid- Ving pinion 25 is" journaled in ya bearing formed integral with the back plate (no1 shown) of sadl apron member.` Motion is transmitted from thereversing gear 24 to :the rack and pinion feed through a train of gears (not shown), the rack gear of said train meshing withthe rackv on the lathe frame. The sliding pinion 25 is formed Yintegral with one end of a sleeve 27which is splined on the feed-rod so as to slide longitudinally thereof and rotate therewith. This sleeve has a tubular extension 28 pinned thereon, which extension is provided near one end with an annular groove 29 adapted to cooperate with a lug 30, which projects horizontally from a depending portion 31 of the slide plate 8 of the lower half of the feed-nut. The opposite end of the tubular extension has a reduced portion `which is fitted into the adjacent end of the pinion sleeve 27 and is pinned therein. y The shoul= der formed by the reduced end portionof the tubular extension is spaced away from the adjacent end of the tubular sleeve 27. forming in connection therewith ay second annular groove 32 adapted to receive the lug 33 of a shifter arm 34.v lith this arrangement, when the sleeve27 is in neutral position, that is, with the piniond 25 out of mesh with the reversing gear 24, the annular groove 29 of the tubular extension-281m directly over the lug, 30 of the lower half-nut 6, thus permitting the lower half-nut to be raised and the screw drive to be employed. When the rack and pin-ion drive .is desired, the sleeve 27 is shiftedtocause the pinion 25 thereof to mesh with the reversing gear 24. ,This shifting ofthe pinion sleeve carries the annular groove 29 of the tubular extension 28 from its position over the lug 30 of the `lower half-nut Sand carrieslthe `body portion of said extension-into position over the lug30, thus preventing' upward movement of the lower Yhalf-'nut- The Vscrewfeed andthe rack and pinion-feed' for the tool-carriage may be reversedthe screwfeed being reversed by reversing thedirection ofrotation of the feed-screw andf'the rack and pinion-feed being reversed, by means of a pinion (not shown)` formed Yon the opposite end of the pinion sleeve 2(7`and adapted to be thrown into mesh with the opposite side of the reversing gear 24y when the sleeve 27 is shifted in the opposite direction.

The hereinbefore describedV arrangement admits of considerable modi'cation without departing from the invention; therefore,l

-do not wish to be limited to the exact details of construction shown and described.

What I claim is v 1. In combination with the feed-screw. and the feed-rod of a lathe, and a gear-shifting sleeve slidable on said feed-rod, ofa. feed-nut comprising a pair of-*half-sections adapted to be closed upon said feedrscrew and to' bereleased therefrom, one of the halfsections of' said feed-nutV having a portion that projects beyond said .feed-rod' and has a lateral extension that .overlaps said sleeve and lies close to the surfacethereof in one position of said sleeve so as to kvbe obstructed thereby but is unobstructed by said sleeve in its opposite position, whereby simultaneous operation of said feed-screw and said feedrod is prevented.

2. In combination with the feed-screw and the feed-rod of a lathe of a feed-nut comprising a pair of half-sections adapted to be closed upon and released from said feed-screw, and a sleeve splind on said feedrod below said feed-nut and adapted to operatively connect said feedfrod with the feed-mechanism of said lathe, said sleeve having an annular groove formed therein, the lower half-section of said feed-nut having a linger extending beneath said sleeve, said finger being adapted in the closed position of said feed-nut to engage the groove in said sleeve to prevent operation Vof the feed-rod, said finger being adapted in the released position of said feed-nut to engage the body portion of said sleeve and thereby prevent the closing of said feed-nut upon ksaid feed-screw during the operation of said feed-rod.

3. In combination with the feed-screw and the feed-rod of a lathe, and a gear-shifting sleeve slidable on said feed-rod, of a feed-nut comprising a pair of half-sections adapted to be closed upon .said feed-screw and to be released therefrom, said sleeve having a portion that moves into and out of the path of a portion of one of said halfnuts, with shifting of the gear, whereby simultaneous operation of said feed-screw and said feed-rod is prevented.

Signed at St. Louis, Missouri, this 30th day of Nov., 1920. f a

, LIONEL A. CARTER. 

